Sensors on-board most commercial aircraft routinely measure certain performance parameters and configuration characteristics of the aircraft during take-off, landing, and flight. Data corresponding to the measurements typically are recorded, or otherwise captured, for subsequent review and evaluation should the need arise. One recording mechanism is generally denoted the “flight data recorder” or “black box,” and has as a design objective surviving a catastrophic failure of the aircraft in which it is placed. Quick access recorders (QARS) or other devices or systems additionally may be used.
Information captured by flight data or other recorders in some commercial aircraft is not always transmitted to any device external to the associated aircraft. U.S. Pat. No. 6,009,356 to Monroe, however, contemplates transmitting certain of the captured information “to ground control stations for real time or near real time surveillance.” See Monroe, Abstract, 11. 7-8. According to the Monroe patent, a “ground tracking station will have the capability of interrogating the in flight data while the aircraft is in flight.” See id., col. 3, 11. 35-37. For at least some other aircraft, recorded information may at times be transmitted for maintenance purposes or in connection with flight operation quality assurance (FOQA) programs.
Shortcomings in assessing braking conditions for landing aircraft have contributed to numerous crashes or other collisions. For more than twenty-five years, recommendations of the U.S. National Transportation Safety Board (NTSB) to the U.S. Federal Aviation Administration (FAA) have mentioned issues with braking action and runway friction. Notwithstanding these multiple recommendations, there remains today a void in fulfilling the need for real-time performance of landing aircraft.
Past recommendations of the NTSB have included proposing to use INS/INU (Inertial Navigation System/Inertial Navigation Unit) data to measure deceleration and on-board equipment for quantitative reports on braking coefficients and analytically derived data for correlation to runway surface conditions. Some progress has been made in this area, although inaccuracies in ground-based friction device measurements and different characteristics of different aircraft types have raised questions about accuracy of analytically-derived friction values. These likely inaccuracies (or, at minimum, imprecisions) cause apprehension among airframe manufacturers and airlines, as potential economic impact of operating aircraft at lower weights than necessary because of inaccurate (or imprecise) calculated friction values is great. Likewise, and perhaps more importantly, the industry may have determined that this margin of error presents unacceptable safety risk. Accordingly, adoption of these past NTSB recommendations does not appear imminent.
Hence, no current (or even currently-anticipated) system provides objective information concerning landing conditions encountered by one aircraft to pilots of subsequently-landing aircraft. Instead, most airports continue to use mechanical, ground-based friction testing devices to collect information. Additionally, subjective reports from landed pilots may be passed, via air traffic controllers or dispatchers, to pilots of landing aircraft. These apparently are the types of reports available to pilots of Southwest Airlines Flight No. 1248 on Dec. 8, 2005, which flight departed the end of a runway and left the airfield boundary at Midway International Airport in Chicago, Ill. As noted by USA Today, the pilots “assumed the runway was in ‘fair’ condition, based on reports from other pilots radioed to them by air traffic controllers.” However, subsequent analysis of objective data “show[ed] the conditions were ‘poor’ at best,” with the runway “so slippery that it would have been difficult for people to walk on, providing minimal traction for the jet's tires as pilots tried to slow down . . . . ” See “Chicago Runway Too Slick at Crash,” http://www.usatoday.com/news/nation/2006-03-01-slick-runway_x.htm.
Indicated by USA Today is that                [t]he accident . . . raises national safety implications because it shows that the system of testing slick runways has potentially fatal flaws. Without accurate information about runway conditions, pilots can stumble into danger without warning . . . .                    The [FAA] says it wants a better way for checking slick runways, but argues that it has not found a system that is reliable for all aircraft.Id. Indeed, according to staff of the NTSB, development of such a system is unlikely for at least the next several years.                        
The FAA is, however, promoting its “NextGen” initiative, a tenet of which includes advanced weather forecasting around problem areas or regions. Current efforts are aimed principally toward reducing flights delays caused by lines of thunderstorms. Nevertheless, other poor-weather scenarios, such as restricted runway operations (particularly during winter), conceivably might merit attention as part of the initiative. For example, among future capabilities proposed for certain airports with high densities of flights (so-called “super-density ops”) is automated distribution of runway braking action reports, which distribution arguably could be used to render greater certainty in determining when runway operations must be restricted.